1. A clearing limit setting device (4) comprising:
a display section (41) that displays, in a two-dimensional field (51) constituted by a length and a thickness of a yarn defect as coordinate axes, a clearing limit (52) that is a boundary line that defines whether to remove a yarn defect from a yarn; and
a processing section (42) that, when at least one first set-point is selected among a plurality of the first set-points (NSL1 to NSL6 and T1 to T4) through which the clearing limit (52) passes and at least one second set-point is input as a movement destination of the selected at least one first set-point, generates a clearing limit (52) that passes through the input at least one second set-point instead of the selected at least one first set-point, and causes the display section (41) to display the newly generated clearing limit (52).
2. The clearing limit setting device (4) as claimed in Claim 1, wherein the processing section (42) causes the display section (41) to simultaneously display the first set-points (NSL1 to NSL6 and T1 to T4) and the clearing limit (52) that passes through the first set-points (NSL1 to NSL6 and T1 to T4), and the at least one second set-point and the clearing limit (52) that passes through the at least one second set-point.
3. The clearing limit setting device (4) as claimed in Claim 1 or 2, comprising a first input unit (51, 55)

that accepts selection of the at least one first set-point, and a second input unit (60) that accepts input of the at least one second set-point.
4. The clearing limit setting device (4) as claimed in Claim 3, wherein the first input unit (51) is the two-dimensional field (51) displayed on the display section (41).
5. The clearing limit setting device (4) as claimed in Claim 3 or 4, wherein
the display section (41) displays a plurality of buttons (55) that respectively correspond to the first set-points (NSL1 to NSL6 and T1 to T4), and
the first input unit (55) is the buttons (55) displayed on the display section (41).
6. The clearing limit setting device (4) as claimed
in any one of Claims 3 to 5, wherein
the display section (41) displays an operation
area (60) that includes a plurality of movement
direction setting buttons (61) that shows movement
directions and accepts selection of the movement
directions, and
the second input unit (60) is the operation area (60) displayed on the display section (41).
7. The clearing limit setting device (4) as claimed
in any one of Claims 1 to 6,
comprising a third input unit (51) that accepts addition of at least one third set-point when the

display section (41) displays the clearing limit (52) that passes through the first set-points (NSL1 to NSL6 and T1 to T4), wherein
the processing section (42) generates the clearing limit (52) that passes through the first set-points and the at least one third set-point added by the third input unit (51) and causes the display section (41) to display the newly generated clearing limit (52).
8. The clearing limit setting device (4) as claimed in Claim 7, wherein the third input unit (51) is the two-dimensional field (51) displayed on the display section (41).
9. The clearing limit setting device (4) as claimed in any one of Claims 1 to 8,
comprising a fourth input unit (51, 55) that accepts deletion of at least one first set-point when the display section (41) displays the clearing limit (52) that passes through the first set-points (NSL1 to NSL6 and T1 to T4), wherein
the processing section (42) generates the clearing limit (52) that passes through the first set-points other than the at least one first set-point deleted by the fourth input unit (51, 55) and causes the display section (41) to display the newly generated clearing limit (52).
10. The clearing limit setting device (4) as claimed
in Claim 9, wherein the fourth input unit (51) is the

two-dimensional field (51) displayed on the display section (41).
11. The clearing limit setting device (4) as claimed
in Claim 9 or 10, wherein
the display section (41) displays a plurality of buttons (55) that respectively correspond to the first set-points (NSL1 to NSL6 and T1 to T4), and
the fourth input unit (55) is the buttons (55) displayed on the display section (41).
12. The clearing limit setting device (4) as claimed
in any one of Claims 1 to 11,
comprising a storage section (43) that stores therein yarn defect data containing the length and the thickness of each of a plurality of yarn defects, wherein
the processing section (42), when newly generating the clearing limit (52) with respect to the currently set clearing limit (52), calculates a first yarn processing result by using the yarn defect data and the currently set clearing limit (52) and calculates a second yarn processing result by using the yarn defect data and the newly generated clearing limit (52), and causes the display section (41) to display the calculated first yarn processing result and the second yarn processing result.
13. The clearing limit setting device (4) as claimed
in any one of Claims 1 to 12,

comprising a storage section (43) that stores therein yarn defect data containing the length and the thickness of each of a plurality of yarn defects, wherein
the processing section (42) generates a guideline (75) by using the yarn defect data, and causes the display section (41) to display the generated guideline (75) along with dots that represent the yarn defects.
14. A yarn winding machine (1) comprising:
a plurality of yarn winding units (2) each including
a yarn supplying section (21) that supplies a yarn;
a winding section (24) that winds the yarn to form a package; and
a yarn monitoring section (22) that monitors the yarn between the yarn supplying section (21) and the winding section (24) to detect a yarn defect; and
a clearing limit setting device (4) as claimed in any one of Claims 1 to 13.